A denitration lance

Abstract

The application discloses a denitration spray gun and belongs to the technical field of flue gas denitration. The denitration spray gun comprises a shell, an outlet opening leading to a flue denitration reaction field is formed in one end of the shell, a center pipe and an outer sleeve pipe are coaxially arranged in the shell, and the center pipe and the outer sleeve pipe are coaxial with the outlet opening; the outer sleeve pipe is arranged outside the center pipe, one end of the center pipe passes through the rear end of the outer sleeve pipe and the other end of the shell in sequence and extends to the outside; the high shear strength fluid breaking flow field is constructed in the outlet opening by cooperating with the high-speed airflow sprayed by the annular cavity through the dynamic shear teeth and the static shear teeth arranged in the axial direction. The high-viscosity and large-molecule denitration reducing agent flowing through the center pipe is broken and refined by the dynamic and static mechanical shearing force when passing through the axial gap between the dynamic shear teeth and the static shear teeth, the particle size of the droplet atomization is reduced, the heterogeneous contact area of the reducing agent and the high-temperature flue gas is enlarged, and the speed of the denitration reaction is improved.

Description

Technical Field

[0001] This invention relates to the field of flue gas denitrification technology, and more specifically, to a denitrification spray gun. Background Technology

[0002] In the flue gas denitrification (such as SNCR or SCR) process of industrial boilers and kilns, the denitrification spray gun is the core component for injecting denitrification reducing agent into the flue. In recent years, with the increasing environmental protection requirements and the development of green and low-carbon technologies, bio-based denitrification agents with biomass extracts as the core component have gradually gained attention due to their wide availability and environmental friendliness.

[0003] However, a key drawback of existing traditional denitrification spray guns when applying bio-based denitrification agents is their tendency to clog. Bio-based denitrification agents typically contain a large number of suspended macromolecules, high-viscosity organic components, or tiny solid particles. Traditional spray guns have small nozzle orifices, and when exposed to high furnace temperatures, the moisture inside the liquid readily vaporizes rapidly at the nozzle head, causing the bio-based components to coke, precipitate, and accumulate at the nozzle, leading to frequent clogging and severely impacting the continuous and stable operation of the system. Furthermore, the viscosity of bio-based denitrification agents is usually greater than that of traditional urea or ammonia solutions, making it difficult for traditional spray guns to adequately shear and break them up. This results in excessively large atomized droplet sizes. Due to the large and unevenly distributed droplets, the denitrification agent cannot react with nitrogen oxides (NOx) in the flue gas. x Insufficient mixing and contact lead to incomplete reaction, low denitrification efficiency, and waste of denitrification agent.

[0004] Therefore, a denitrification spray gun is proposed. Summary of the Invention

[0005] In view of the problems existing in the prior art, the purpose of this invention is to provide a denitrification spray gun that can improve denitrification efficiency.

[0006] To solve the above problems, the present invention adopts the following technical solution.

[0007] A denitrification spray gun includes a housing, one end of which has a discharge port leading to the flue gas denitrification reaction field;

[0008] It also includes a central tube and an outer tube coaxially arranged inside the housing, and both the central tube and the outer tube are coaxial with the discharge port;

[0009] The outer sleeve is fitted over the outside of the central tube, and one end of the central tube passes through the rear end of the outer sleeve and the other end of the shell and extends to the outside.

[0010] The outer sleeve has an opening at one end near the discharge port, and the open end of the outer sleeve is sealed and fixedly connected to the inner wall of the shell.

[0011] A first annular groove is provided on the outer circumferential surface of the central tube, and an installation ring is rotatably fitted inside the first annular groove;

[0012] The outer periphery of the mounting ring is provided with several drive blades that are evenly spaced and inclined in the circumferential direction.

[0013] A connecting rod is fixedly connected to the side wall of the mounting ring, and an outer scraper is fixedly installed at the extended end of the connecting rod. The outer scraper slides against the side wall of the discharge port, and the scraping surface of the outer scraper is set as a guide slope.

[0014] An inner scraper is also fixedly connected to the connecting rod, and the inner scraper slides and fits against the outer circumferential surface of the central tube near the discharge port.

[0015] The outer scraper is uniformly provided with several moving shearing teeth on one side facing the axis of the central tube. These moving shearing teeth are located in front of the discharge end of the central tube to reduce the atomized particle size of the high-viscosity bio-based denitrification reducing agent through mechanical shearing, thereby expanding the heterogeneous contact area between the reducing agent and the flue gas.

[0016] Furthermore, a mounting rod extending into the discharge port is fixedly installed on the end face of the central tube near the discharge port. A static shearing ring is fixedly installed on the mounting rod, and several static shearing teeth are provided on the static shearing ring along the circumferential direction. The dynamic shearing teeth and the static shearing teeth are staggered in the axial direction.

[0017] Furthermore, several mounting grooves are evenly provided on the inner wall of the outer sleeve along the circumference. An elastic striking block is fixedly installed in the mounting groove. The cross-sectional dimension of the elastic striking block is smaller than the inner opening dimension of the mounting groove, and the free end of the elastic striking block extends out of the mounting groove.

[0018] Furthermore, the resilient striking block includes a metal bellows and a spherical protrusion fixedly installed at its free end; the rear end of the metal bellows is fixed to the bottom of the mounting groove.

[0019] A return spring is provided in the hollow area inside the metal bellows, and the two ends of the return spring are fixedly connected to the two ends inside the metal bellows.

[0020] Furthermore, an exhaust port communicating with the mounting groove is provided on the inner wall of the metal bellows.

[0021] Furthermore, a guide groove is inclinedly formed on the side wall of the mounting ring;

[0022] A fixed rod and a sliding rod are respectively provided at both ends of one side wall of the drive blade. The fixed rod is fixed to one end of the drive blade and rotatably connected to the side wall of the mounting ring; the sliding rod is fixed to the other end of the drive blade and slides within the guide groove.

[0023] The drive blades are made of high-temperature resistant flexible spring steel sheets and are prefabricated with a wind-facing bending structure.

[0024] Furthermore, the extended end of the connecting rod is provided with a radially extending sliding groove, in which a slider is slidably installed. The slider is fixedly connected to the outer scraper, and a compression spring is clamped between the outer scraper and the end face of the sliding groove.

[0025] Furthermore, both the outer and inner scrapers are entirely coated with a high-temperature resistant, self-lubricating ceramic coating.

[0026] Furthermore, an axially extending guide cavity is provided inside the mounting rod;

[0027] An air inlet is provided on the side wall of the mounting rod, with the inlet end of the air inlet pointing towards the annular cavity formed between the outer wall of the central tube and the inner wall of the outer sleeve; a pressure relief hole is provided on the side wall of the mounting rod parallel to the axis of the central tube, with the pressure relief hole pointing towards the discharge port, and the pressure relief hole is connected to the interior of the guide cavity.

[0028] Furthermore, the mounting rod is made of stainless steel, and its outer circumference is polished to form a mirror-like structure with a surface roughness Ra≤0.2μm.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] (1) In this scheme, the high-speed airflow ejected from the annular cavity impacts and drives the blades, causing the mounting ring and the moving shear teeth to rotate; the moving shear teeth and the stationary shear teeth on the stationary shear ring are axially staggered, so that the denitrification reducing agent is sprayed out after being sheared and broken. When the high-viscosity, large-molecule denitrification reducing agent flowing through the central tube is forcibly passed through the gap between the moving shear teeth and the stationary shear teeth, it is strongly "shorn" and torn, which realizes the reduction of droplet atomization particle size, expands the heterogeneous contact area between the reducing agent and the high-temperature flue gas, and improves the speed and completeness of the denitrification reaction and the comprehensive utilization rate of the agent.

[0031] (2) In this scheme, the rotating outer scraper uses a flexible bonding method driven by centrifugal force and compression spring to clean the inner wall of the discharge port in real time. At the same time, the radial impact vibration generated by the periodic collision of the connecting rod with the elastic striking block, as well as the high-pressure directional pneumatic shock wave released periodically by the pressure relief hole, are used to crush and smoothly peel off the strong sticky slough material in the early stage of coking under the superposition of mechanical kinetic energy and transient airflow. This prevents the secondary hardening and accumulation of slough debris at the blade edge and nozzle, and ensures the long-term continuous smooth flow of the spray gun discharge port.

[0032] (3) The drive blade adopts a flexible spring steel sheet with a prefabricated windward bending structure. When the speed drops instantaneously due to sudden obstruction caused by external coking material, the fluid pressure difference accumulated in the annular cavity can be used to force the blade to undergo elastic deformation and increase the windward cross-sectional area, thereby spontaneously amplifying the tangential output torque to forcibly overcome the obstruction. In addition, the high-temperature resistant self-lubricating ceramic coating on the surface of the outer scraper reduces the physical adhesion between the slag and the metal interface, strengthens the thermal shock resistance and wear resistance of the core components, and extends the safe and continuous service life of the entire cutting and coking mechanism in extreme high temperature and dusty environments. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0034] Figure 2 This is a front cross-sectional view of the housing of the present invention;

[0035] Figure 3 For the present invention Figure 2 Enlarged structural diagram at point A;

[0036] Figure 4 For the present invention Figure 3 Enlarged structural diagram at point B;

[0037] Figure 5 For the present invention Figure 3 Enlarged structural diagram at point C;

[0038] Figure 6 This is a schematic diagram of the combined structure of the sliding groove, the slider, and the compression spring of the present invention;

[0039] Figure 7 This is a schematic diagram of the combined structure of the guide groove, fixed rod, and sliding rod of the present invention;

[0040] Figure 8 This is a schematic diagram of the mounting ring and drive blade of the present invention.

[0041] Explanation of the labels in the diagram:

[0042] 1. Shell; 101. Discharge port; 2. Central tube; 201. First annular groove; 3. Outer tube; 301. Air inlet pipe; 4. Mounting ring; 5. Drive blade; 6. Connecting rod; 7. Outer scraper; 8. Inner scraper; 9. Moving shearing teeth; 10. Mounting rod; 11. Static shearing ring; 1101. Static shearing teeth; 12. Elastic striking block; 1201. Metal bellows; 1202. Spherical protrusion; 1203. Return spring; 1204. Exhaust port; 13. Guide groove; 14. Fixed rod; 15. Sliding rod; 16. Sliding groove; 17. Sliding block; 18. Compression spring; 19. Flow guide cavity; 20. Air inlet; 21. Pressure relief hole; 22. Annular cavity. Detailed Implementation

[0043] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0044] Example 1:

[0045] Please see Figures 1 to 8 A denitrification spray gun includes a housing 1, one end of which is provided with a discharge port 101 leading to the flue gas denitrification reaction field;

[0046] It also includes a central tube 2 and an outer tube 3 coaxially disposed inside the housing 1, and both the central tube 2 and the outer tube 3 are coaxial with the discharge port 101;

[0047] The outer sleeve 3 is fitted over the outside of the central tube 2. One end of the central tube 2 passes through the rear end of the outer sleeve 3 and the other end of the shell 1 and extends to the outside. The ratio of the inner diameter of the outer sleeve 3 to the outer diameter of the central tube 2 is 1.5-2. An annular cavity 22 is formed between the outer wall of the central tube 2 and the inner wall of the outer sleeve 3.

[0048] The outer sleeve 3 has an opening at one end near the discharge port 101, and the opening end of the outer sleeve 3 is sealed and fixedly connected to the inner wall of the housing 1; an air inlet pipe 301 is fixedly inserted through the side wall of the outer sleeve 3, and the air inlet pipe 301 is connected to the internal cavity of the outer sleeve 3; the other end of the air inlet pipe 301 passes through the side wall of the housing 1 and is used to connect with an external high-pressure air source.

[0049] A first annular groove 201 is provided on the outer circumferential surface of the central tube 2, and an installation ring 4 is rotatably sleeved in the first annular groove 201;

[0050] The outer periphery of the mounting ring 4 is provided with several drive blades 5 evenly spaced and inclined in the circumferential direction; when the high-pressure airflow flows along the annular cavity 22 between the outer wall of the central tube 2 and the inner wall of the outer sleeve tube 3, the high-pressure airflow impacts the inclined drive blades 5, thereby generating tangential thrust and driving the mounting ring 4 to rotate around the axis of the central tube 2.

[0051] A connecting rod 6 is fixedly connected to the side wall of the mounting ring 4. An outer scraper 7 is fixedly installed at the extended end of the connecting rod 6. The outer scraper 7 slides against the side wall of the discharge port 101, and the scraping surface of the outer scraper 7 is set as a guide slope. During the process of the mounting ring 4 driving the outer scraper 7 to rotate through the connecting rod 6, the outer scraper 7 mechanically scrapes and peels off the coking material or precipitate adhering to the surface of the discharge port 101, thereby keeping the discharge port 101 unobstructed.

[0052] An inner scraper 8 is also fixedly connected to the connecting rod 6. The inner scraper 8 slides and fits against the outer circumferential surface of the central tube 2 near the discharge port 101. During the process of the mounting ring 4 rotating around the axis of the central tube 2, the inner scraper 8 and the outer scraper 7 mechanically scrape the outer circumferential surface of the central tube 2 and the inner wall of the discharge port 101 of the shell 1 simultaneously.

[0053] The outer scraper 7 is uniformly provided with a number of moving shear teeth 9 on one side facing the axis of the central tube 2. The moving shear teeth 9 are located in front of the discharge end of the central tube 2 to reduce the atomized particle size of the high viscosity bio-based denitrification reducing agent through mechanical shearing, thereby expanding the heterogeneous contact area between the reducing agent and the flue gas. The moving shear teeth 9 form a cutting surface when they rotate with the mounting ring 4. When the denitrification reducing agent flowing through the central tube 2 is sprayed out, it passes through the cutting surface and is mechanically broken by the moving shear teeth 9 and cross-sheared atomized by the high pressure airflow from the annular cavity 22.

[0054] A mounting rod 10 extending into the discharge port 101 is fixedly installed on the end face of the central tube 2 near the discharge port 101. A static shear ring 11 is fixedly installed on the mounting rod 10, and several static shear teeth 1101 are provided circumferentially on the static shear ring 11. The moving shear teeth 9 and the static shear teeth 1101 are staggered in the axial direction, forming a dynamic and static two-stage shearing and crushing structure for the denitrification reducing agent. High-viscosity macromolecules are "shorn" and strongly crushed when passing through the gap between the moving and static teeth, reducing the atomized particle size. The mounting rod 10 is made of stainless steel, and the outer circumferential surface of the mounting rod 10 is polished to form a mirror structure with a surface roughness Ra≤0.2μm to reduce the adhesion of coking material to the surface of the mounting rod 10.

[0055] The axial distance between the moving shear tooth 9 and the stationary shear ring 11 is... The ratio of the diameter of the outlet 101 to the diameter of the outlet end of the central tube 2 is 1 / 2. to .

[0056] Both the outer scraper 7 and the inner scraper 8 are entirely covered with a high-temperature resistant, self-lubricating ceramic coating.

[0057] Because the front end of the denitrification spray gun is exposed to harsh conditions of high temperature and high dust for a long time, the detached coking material is prone to secondary accumulation at the mechanical cutting edge. By introducing a high-temperature resistant self-lubricating ceramic coating on the substrate surface of the outer scraper 7 and the inner scraper 8, the high hardness of the ceramic material improves the wear resistance and thermal shock resistance of the scraper. On the other hand, the self-lubricating properties of the coating reduce the adhesion between the coking material and the scraper surface. This ensures that the detached coking debris can slide off smoothly during mechanical scraping, preventing secondary adhesion and accumulation of coking material on the scraper surface, and ensuring the long-term continuous operation of the descaling mechanism.

[0058] An external high-pressure gas source is introduced into the annular cavity 22 between the central tube 2 and the outer tube 3 through the air inlet pipe 301. At the same time, the reaction solution is injected into the central tube 2.

[0059] When the high-speed, high-pressure airflow flows along the annular cavity 22, it impacts the drive blades 5 that are rotated and mounted on the central tube 2. Because the blades are designed with uniform circumferential spacing and an inclined structure, the impact force of the high-pressure airflow is converted into tangential thrust, thereby driving the entire mounting ring 4 to rotate at high speed around the axis of the central tube 2.

[0060] As the mounting ring 4 rotates, the connecting rod 6 fixedly connected to it will synchronously drive the inner scraper 8 and the outer scraper 7 to rotate. At this time, the inner scraper 8 is tightly slidably attached to the outer peripheral surface of the central tube 2 near the discharge port 101, while the outer scraper 7 is tightly slidably attached to the inner wall surface of the discharge port 101 of the housing 1.

[0061] During the synchronous rotation of the inner scraper 8 and the outer scraper 7, the coking and precipitates adhering to the outer wall of the central tube 2 and the inner wall of the discharge port 101 of the housing 1 are continuously and powerfully scraped mechanically. Combined with the unique guiding slope of the outer scraper 7, the scraped-off impurities are smoothly guided and peeled off for discharge. This achieves real-time self-cleaning during spray gun operation, thereby reducing the risk of coking and clogging at the discharge port 101 and ensuring that the spray gun can operate continuously and unimpeded for a long time.

[0062] After the denitrification reducing agent solution is sprayed out from the central tube 2, it undergoes a violent cross-collision with the high-pressure airflow sprayed out from the annular cavity 22 and is sheared into small particles. Then, it passes head-on through the dynamic cutting surface formed by the high-speed rotation of the moving shear teeth 9 on the inner side of the outer scraper 7 with the mounting ring 4. At this point, the reducing agent solution is mechanically crushed by the high-speed rotating moving shear teeth 9.

[0063] Subsequently, the reducing agent is further subjected to a dynamic and static dual-stage shearing and crushing structure, which consists of static shearing teeth 1101 fixed on the mounting rod 10 and rotating dynamic shearing teeth 9 arranged alternately in the axial direction.

[0064] Therefore, high-viscosity, large-molecule reducing agent liquids are also "shorn" and subjected to strong crushing impact when forcibly passing through the tiny axial gap between the moving and stationary shearing teeth 1101. Under the dual action of mechanical shearing force and high-pressure airflow cross-shearing, the droplets of the denitrification reducing agent are deeply torn apart, and the atomized particle size is reduced. This increases the contact area between the reducing agent and the flue gas, making the denitrification reaction faster and more complete, thereby improving the overall denitrification efficiency and reagent utilization rate.

[0065] like Figure 2 , Figure 3As shown, several mounting grooves are evenly distributed circumferentially on the inner wall of the outer sleeve 3. An elastic striking block 12 is fixedly installed in the mounting groove. The cross-sectional dimension of the elastic striking block 12 is smaller than the inner opening dimension of the mounting groove, and the free end of the elastic striking block 12 extends out of the mounting groove. During the process of the mounting ring 4 driving the connecting rod 6 to rotate, the connecting rod 6 periodically collides with the elastic striking block 12, so that the elastic striking block 12 undergoes elastic deformation and retracts into the mounting groove. At the same time, the connecting rod 6 vibrates under the impact force, so that the outer scraper 7 is subjected to radial impact force while sliding and scraping, so as to shake off the adhering material on the surface of the outer scraper 7.

[0066] The elastic striking block 12 includes a metal bellows 1201 and a spherical protrusion 1202 fixedly installed at its free end; the rear end of the metal bellows 1201 is fixed to the bottom of the mounting groove.

[0067] A return spring 1203 is provided in the hollow area inside the metal bellows 1201. The two ends of the return spring 1203 are fixedly connected to the two ends inside the metal bellows 1201, respectively.

[0068] The inner wall of the metal bellows 1201 is provided with an exhaust hole 1204 that communicates with the mounting groove, and the space between the mounting groove and the inner wall of the outer sleeve 3 and the outer wall of the central tube 2 is connected, so the airflow flowing in the outer sleeve 3 will enter the mounting groove.

[0069] When the connecting rod 6 rotates and presses inward against the elastic striking block 12, the gas inside the metal bellows 1201 is passively compressed to form a high-pressure air cushion for impact buffering.

[0070] After the connecting rod 6 slides past the highest point of the elastic striking block 12, driven by the elastic rebound force of the reset spring 1203, the volume of the metal bellows 1201 increases and it quickly pops out to reset. Part of the high-pressure airflow in the annular cavity 22 flows back into the metal bellows 1201 with increased volume through the mounting groove and the exhaust hole 1204, and uses the pressure difference to drive the elastic striking block 12 to quickly pop out to reset.

[0071] During this process, the outwardly ejected elastic striking block 12 presses against the rear edge of the connecting rod 6 through the guide arc surface of the spherical protrusion 1202, assisting in pushing the connecting rod 6, thereby accelerating the overall rotation speed of the mounting ring 4 and the scraper assembly, thus improving the cleaning and impact effect of the outer scraper 7.

[0072] like Figure 7 , Figure 8 As shown, a guide groove 13 is inclinedly provided on the side wall of the mounting ring 4;

[0073] A fixed rod 14 and a sliding rod 15 are respectively provided at both ends of one side wall of the drive blade 5. The fixed rod 14 is fixed to one end of the drive blade 5 and rotatably connected to the side wall of the mounting ring 4; the sliding rod 15 is fixed to the other end of the drive blade 5 and slides within the guide groove 13, and the fixed rod 14 is located exactly on the extension line of the guide groove 13.

[0074] The drive blade 5 is made of high-temperature resistant flexible spring steel sheet and is prefabricated as an upwind bending structure. The critical pressure difference for deformation of the drive blade 5 is set to... (ranging from 0.15 MPa to 0.3 MPa), when the outer scraper 7 is obstructed, causing the back pressure of the airflow in the annular cavity 22 to be greater than or equal to this critical pressure difference. At this time, the driving blade 5 overcomes its own elastic stiffness K and undergoes elastic flat deformation to increase the cross-sectional area exposed to wind.

[0075] When the outer scraper 7 is obstructed by coking material, causing the rotational speed of the mounting ring 4 to decrease, a high-pressure airflow is generated in the annular cavity 22 between the outer wall of the central tube 2 and the inner wall of the outer sleeve tube 3. Under the impact of the high-pressure airflow accumulated in the annular cavity 22, the drive blade 5 undergoes an elastic bending deformation that spreads in the opposite direction to the windward side, forcing the slide rod 15 to slide along the guide groove 13 towards the fixed rod 14. At this time, the windward cross-sectional area of ​​the drive blade 5 increases accordingly. When the rotational speed recovers, the drive blade 5 returns to the pre-formed windward bending structure by its own elastic restoring force, thereby amplifying the tangential torque of the drive mounting ring 4 and achieving the effect of automatically overcoming obstruction.

[0076] like Figure 6 As shown, the extended end of the connecting rod 6 is provided with a radially extending sliding groove 16. A slider 17 is slidably installed in the sliding groove 16. The slider 17 is fixedly connected to the outer scraper 7, and a compression spring 18 is sandwiched between the end face of the outer scraper 7 and the sliding groove 16. When the mounting ring 4 drives the connecting rod 6 to rotate, the outer scraper 7 slides radially outward along the sliding groove 16 under the combined drive of its own centrifugal force and the elastic force of the compression spring 18, so that the scraping surface of the outer scraper 7 always adaptively and tightly adheres to the inner wall of the discharge port 101, ensuring the decoking effect.

[0077] like Figure 5 As shown, the mounting rod 10 has an axially extending guide cavity 19 inside;

[0078] An air inlet 20 is provided on the side wall of the mounting rod 10, with the inlet end of the air inlet 20 pointing towards the annular cavity 22 formed between the outer wall of the central tube 2 and the inner wall of the outer sleeve 3; a pressure relief hole 21 is provided on the side wall of the mounting rod 10, which is parallel to the axis of the central tube 2, and points towards the discharge port 101, and the pressure relief hole 21 is connected to the interior of the guide cavity 19.

[0079] When the spray gun is working, the atomized high-pressure airflow flowing inside the outer sleeve 3 accumulates in the annular cavity 22. A portion of this high-pressure airflow, driven by the pressure difference, passes through the air inlet 20 and is guided into the guide cavity 19 inside the mounting rod 10, and finally is axially ejected at high speed from the pressure relief hole 21 towards the discharge port 101. At this time, as the outer scraper 7 rotates circumferentially around the axis of the central tube 2 with the mounting ring 4, the outer scraper 7 periodically sweeps across the front of the pressure relief hole 21 on its revolution track. Whenever the outer scraper 7 sweeps across this area, the aerodynamic shock wave formed by the high-pressure directional airflow ejected at high speed from the pressure relief hole 21 performs directional high-pressure pneumatic purging on the scraping surface of the outer scraper 7.

[0080] The coordinated operation of this mechanical rotation and directional airflow jet creates a periodic high-pressure purging self-cleaning structure on the surface of the outer scraper 7, based on rotational shielding. In the early stages of coking when the material is highly viscous, the dynamic shearing force of the high-speed airflow and the combined mechanical scraping effectively disperse and peel off the initial coking material adhering to the surface of the outer scraper 7. This prevents secondary adhesion and hardening of the peeled coking debris on the scraper body surface, thus improving the continuous service life and anti-clogging performance of the entire cutting and coking mechanism under extremely harsh high-temperature conditions.

[0081] In this embodiment, since the front end of the spray gun is deeply inserted into the high-temperature flue, the high-pressure airflow flowing inside the outer sleeve 3 also serves as a cooling medium. The metal bellows 1201, the return spring 1203, and the sliding groove 16 are all located on the direct convection cooling path of the high-speed cold airflow, keeping their service temperature below the creep temperature of the spring steel. At the same time, the mating surfaces of the sliding groove 16 and the slider 17 are coated with a high-temperature anti-coking coating, and the depth of the sliding groove 16 is greater than the maximum radial displacement of the slider 17 under thermal expansion, in order to avoid jamming due to thermal expansion.

[0082] The above are merely preferred embodiments of the present invention; however, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concept, should be covered within the scope of protection of the present invention.

Claims

1. A denitrification spray gun, comprising a housing (1), wherein one end of the housing (1) is provided with a discharge port (101) leading to the flue gas denitrification reaction field. Its features are: It also includes a central tube (2) and an outer tube (3) coaxially disposed inside the housing (1), and the central tube (2) and the outer tube (3) are both coaxial with the discharge port (101); The outer sleeve (3) is fitted over the outside of the central tube (2), and one end of the central tube (2) passes through the rear end of the outer sleeve (3) and the other end of the shell (1) and extends to the outside. The outer sleeve (3) has an opening at one end near the discharge port (101), and the opening end of the outer sleeve (3) is sealed and fixedly connected to the inner wall of the shell (1); an air inlet pipe (301) is fixedly inserted through the side wall of the outer sleeve (3), and the air inlet pipe (301) is connected to the internal cavity of the outer sleeve (3); the other end of the air inlet pipe (301) passes through the side wall of the shell (1) and is used to connect with an external high-pressure air source; The outer circumferential surface of the central tube (2) is provided with a first annular groove (201), and an installation ring (4) is rotatably sleeved in the first annular groove (201). The mounting ring (4) has several driving blades (5) evenly spaced and inclined along the circumferential direction on its outer periphery. A connecting rod (6) is fixedly connected to the side wall of the mounting ring (4), and an outer scraper (7) is fixedly installed at the extended end of the connecting rod (6). The outer scraper (7) slides against the side wall of the discharge port (101), and the scraping surface of the outer scraper (7) is set as a guide slope. An inner scraper (8) is also fixedly connected to the connecting rod (6), and the inner scraper (8) slides and fits against the outer circumferential surface of the central tube (2) near the discharge port (101); The outer scraper (7) is uniformly provided with a number of moving shearing teeth (9) on one side facing the axis of the central tube (2), and the number of moving shearing teeth (9) is located in front of the discharge end of the central tube (2).

2. The denitrification spray gun according to claim 1, characterized in that: A mounting rod (10) extending into the discharge port (101) is fixedly installed on the end face of the central tube (2) near the discharge port (101). A static shearing ring (11) is fixedly installed on the mounting rod (10). A plurality of static shearing teeth (1101) are provided on the static shearing ring (11) along the circumferential direction. The dynamic shearing teeth (9) and the static shearing teeth (1101) are staggered in the axial direction.

3. A denitrification spray gun according to claim 2, characterized in that: The inner wall of the outer sleeve (3) is provided with several mounting grooves evenly distributed along the circumference. An elastic striking block (12) is fixedly installed in the mounting groove. The cross-sectional dimension of the elastic striking block (12) is smaller than the inner opening dimension of the mounting groove, and the free end of the elastic striking block (12) extends out from the mounting groove.

4. A denitrification spray gun according to claim 3, characterized in that: The elastic striking block (12) includes a metal bellows (1201) and a spherical protrusion (1202) fixedly installed at its free end; the rear end of the metal bellows (1201) is fixed to the bottom of the mounting groove; The hollow area inside the metal bellows (1201) is provided with a return spring (1203), and the two ends of the return spring (1203) are fixedly connected to the two ends inside the metal bellows (1201).

5. A denitrification spray gun according to claim 4, characterized in that: The inner wall of the metal bellows (1201) is provided with an exhaust hole (1204) that communicates with the mounting groove.

6. A denitrification spray gun according to claim 1, characterized in that: The mounting ring (4) has a guide groove (13) inclinedly opened on its side wall; A fixed rod (14) and a sliding rod (15) are respectively provided at both ends of one side wall of the drive blade (5). The fixed rod (14) is fixed to one end of the drive blade (5) and rotatably connected to the side wall of the mounting ring (4); the sliding rod (15) is fixed to the other end of the drive blade (5) and slides within the guide groove (13). The drive blade (5) is made of high-temperature resistant flexible spring steel sheet and is prefabricated as a wind-facing bending structure.

7. A denitrification spray gun according to claim 1, characterized in that: The extension end of the connecting rod (6) is provided with a radially extending sliding groove (16), and a slider (17) is slidably installed in the sliding groove (16). The slider (17) is fixedly connected to the outer scraper (7), and a compression spring (18) is sandwiched between the end face of the outer scraper (7) and the sliding groove (16).

8. A denitrification spray gun according to claim 1, characterized in that: The surfaces of both the outer scraper (7) and the inner scraper (8) are entirely covered with a layer of high-temperature resistant self-lubricating ceramic coating.

9. A denitrification spray gun according to claim 2, characterized in that: The mounting rod (10) has an axially extending guide cavity (19) inside. An air inlet (20) is provided on the side wall of the mounting rod (10), and an annular cavity (22) is formed between the outer wall of the central tube (2) and the inner wall of the outer sleeve (3); the inlet end of the air inlet (20) points to the annular cavity (22); a pressure relief hole (21) parallel to the axis of the central tube (2) is provided on the side wall of the mounting rod (10), the pressure relief hole (21) points to the discharge port (101), and the pressure relief hole (21) is connected to the interior of the guide cavity (19).

10. A denitrification spray gun according to claim 2, characterized in that: The mounting rod (10) is made of stainless steel, and the outer peripheral surface of the mounting rod (10) is polished to form a mirror surface structure.

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